A.T. Robertson Commentary John 10:20

"And many of them said, He hath a demon, and is mad; why hear ye him?" — John 10:20 (ASV)

He has a demon and is mad (δαιμονιον εχε κα μαινετα). As some had already said (7:20; 8:48 with the addition of "Samaritan"). So long before in Mr 3:21. An easy way of discounting Jesus.